Some graphs, any suggestions

[spamula9]

I just got a BFD 1124p, I tried it out some using manual measurements. My sub is a SVS PB12-Plus/2. The blue curve is measured without BFD, the green and red are two different filter settings with a house curve. It sounds weaker now, such as on the scene from LOTR3 with those big elephant things come into the battle. I use to feel them stomping, now I don't. Should I try lowering stuff above 20 Hz, or just start all over. I eventually will want to hook everything up to a computer and use REW so I can try moving the sub around more (laptop is too old). Before I got the BFD I did the craw around the floor method to find the location of the sub that had the highest SPL reading. That might have just been the place where the peak at 45ish HZ was the worst. I'm new to all this and trying to learn as a go with all this HT stuff, I could be wrong with my thinking above. Let me know if you need more info.

[brucek]

I think what you're experiencing is standard fare once you stop listening to the so called "one note bass".

When you have a peak as you did at 45Hz, you tend to set your sub level to this single note and so the under 45Hz information is somewhat lost.

Once you equalize that peak out as you've done so nicely, that information under 45Hz is revealed. It seems thin now, but the standard advice is to give it time.

You also need to reset the sub levels with your standard receiver speaker level setup to ensure the sub level is now correct after eq'ing. Also you can use REW and set the balance between the sub and mains to attain the same objective.....

brucek

[Wayne A. Pflughaupt]

Other reasons why it might sound “thin:” You might need to turn the sub up, since you did such a substantial dial-down of the 45-Hz peak.

Also, your house curve may not be steep enough. And I suggest shelving it at 30 Hz or so – you have it shelved at around 45 Hz, which is pretty high.

Regards,
Wayne

[SteveCallas]

brucek wrote:

I think what you're experiencing is standard fare once you stop listening to the so called "one note bass".

Absolutely, most people are accustomed to innacurate bass. A peaked response like spam had or even a high distortion driver will add artificial oomph, making lots of varied types of bass all sound pretty similar because the same range of frequencies is being "stimulated" most often. Now I'm not saying it's wrong, as people gotta go with what they like, but a flat FR with low distortion and plenty of headroom will allow more subtleties and variances in the bass to shine through - definitely a more accurate reproduction. You'll also get much more effect from infrasonics too, as a peaked response like spam had is almost negating infrasonics entirely. What you thought was low before wasn't really that low

For the time being, I agree that you should recheck your levels and probably even run your sub hot for a while just to ween you in on more accurate bass. Eventually you'll probably find yourself wanting to turn it back down to more even levels. If not, don't feel bad, I know of at least one LLT owner who prefers a peaked response too

[Sonnie]

brucek wrote:

You also need to reset the sub levels with your standard receiver speaker level setup to ensure the sub level is now correct after eq'ing.

Wayne A. Pflughaupt wrote:

Other reasons why it might sound “thin:” You might need to turn the sub up, since you did such a substantial dial-down of the 45-Hz peak.

SteveCallas wrote:

For the time being, I agree that you should recheck your levels and probably even run your sub hot for a while just to ween you in on more accurate bass.

I'm hearing a loud echo... so I'll just ditto the above.

You do realize you cut your bass by 20db or more when you cut that peak? That is an awful lot, so yeah... no doubt it will sound weak. In case no one else has mentioned it... turn your bass up and up and up...

brucek wrote:

I think what you're experiencing is standard fare once you stop listening to the so called "one note bass".

SteveCallas wrote:

Absolutely, most people are accustomed to innacurate bass.

Wayne A. Pflughaupt wrote:

Also, your house curve may not be steep enough. And I suggest shelving it at 30 Hz or so – you have it shelved at around 45 Hz, which is pretty high.

We experienced this exact situation this weekend. Walter preferred the bass when it had a peak at 30-35Hz, most likely because he's use to listening to car stereo's for so long. Even Rodny preferred it over the flat response. I was able to give them back most of what they were missing with a house curve shelved at about 35Hz.


It is truly amazing at how much I have come to appreciate a flat response after listening to it for hours on end (with music especially). I hardly ever listen to many CDs, but I do watch quite a few DVD concerts. I have come to prefer the flatter response over the house curve. But I'd have to say the house curve will definitely give you back some of that low end you are missing, provided you level match your sub with your speakers....

[Blaser]

VERY INFORMATIVE AND NICE REPLIES FROM THE SHACK BOSSES There's simply nothing I can add, except maybe that I am facing exactly this situation now, and discovered that after taming a 20 db peak at 35 Hz, my sub (which was "artificaily" strong before BFD) is lacking headroom now!!

Nevertheless, I can't agree SQ isn't better!!! But yes, the subs need much more power to give me the slam I had at 35 Hz, along with all other frequencies down to.... That's the point indeed!!

Blaser

[spamula9]

Thanks guys for all those responses. When I get home I got some playing around to do. I did turn up the gain some on the sub while watching the movie later (didn't do much for me, didn't spend much time playing around with it though, I had to get to bed by then ) but I think changing the house curve will help. I had used one I saw here on the forum somewhere. Would the one I saw you post Brucek be a good starting point?:

60Hz with an 80dBSPL target level and a housecurve of:
30 5.0
40 3.0
50 1.0
60 0.0

As for as running the sub hot. Is there a too hot, assuming your sub can handle it? Before the BFD I had the receiver at -10 or maybe -8 and the gain on the sub at 1/4 or 1/3 I believe. The graphs that were done after BFD was applied had the receiver at -6, which is the level that started making the BDF clip with scenes that had high levels, the sub gain stayed the same. I don't want to have the sub run out of head room and clip it. Am I safe as long as I don't turn the sub gain to the max or could I have problems with the gain 1/2 or 3/4 the way up.

When I get a chance I'll re-due the filters with a new house curve and adjust levels and see what I get. Thanks again for your help.

[brucek]

Would the one I saw you post Brucek be a good starting point?:

Not if you have a crossover of 80Hz. That one is for a 60Hz crossover.
Simply start with:
30 5.0
80 0.0

Am I safe as long as I don't turn the sub gain to the max

Depends on the level coming into the sub. Since its from your receiver and the BFD is a unity gain device, you are fine. Especially since you used so much cut....

brucek

[SteveCallas]

If BFD is clipping when your receiver is at -6, you can either turn the receiver sub level down a bit and turn the sub's gain up, or you can switch the sensitivity of the BFD. The Plus/2 should be pretty bulletproof due to built in limiters in its amp. If you typically listen at reference levels though, then you probably need more sub to begin with. But if you listen in the -15 to -10 range, running the sub a few dbs hot shouldn't be a problem.

[Wayne A. Pflughaupt]

As for as running the sub hot. Is there a too hot, assuming your sub can handle it?

Well, you don’t want the sub so hot that it’s an annoyance. I mean, you don’t want car doors closing to sound like a sonic boom, do you? The goal isn’t to run the sub as hot as you can, but to blend it in with the rest of the system.

Regards,
Wayne

[spamula9]

Wayne A. Pflughaupt wrote:

Well, you don’t want the sub so hot that it’s an annoyance. I mean, you don’t want car doors closing to sound like a sonic boom, do you?

Well maybe if its a chick flick that would be all bass action I would be able to get. j/k

I've had a hum coming from my sub ever sense I connected to the BFD, I've read the threads about this problem and haven't been to worried about it. I just noticed though when I put the BFD on filter 10 the hum goes away (if I put my ear right up to the sub I still can hear a slight hum nothing bad though). On filters 1-9 you can easly here it. Is there something wrong with my BFD? Ever hear of this. Also with all filters off its the same.

[brucek]

Do you mean program #10 or filter #10 of any program slot?

[spamula9]

I mean program #10. Also I can only change filter 1 and 2 for program slot #10.

[brucek]

I've only used program slots 4, 5, 6. Never needed any more. I believe all ten program slots can be programmed with any twelve filter setings of your choice. Be sure the mode of all the unused filters is "OF" in a program slot, so that you don't accidentally enable feedback destroy mode...

brucek